Patent GB-408991-A (GB)
Title: An improved method of producing multi-colour photographs and kinematograph pictures
IPC: G03C7/28
Filed: 1932-07-18
Abstract: 408,991. Colour photography. GASPAR, B., 38, Innsbruckerstrasse, Schoneberg, Berlin. July 18, 1932, No. 20279. Convention date, July 20, 1931. [Class 98 (ii).] Multicolour photographs and kinematograph films are produced on a plurality of differently coloured silver - halide layers sensitized for different spectral regions in such a manner that the upper part layer is sensitized for rays allowed to pass by its own colour, and the lower part layer or layers is or are sensitized to rays which pass through the part layer itself and through the part layer or layers above the same the part layers being copied behind black-andwhite or coloured master or part images and subsequently converted to dyestuff images by destruction or dissolution of the dyestuff at the image or non-image portions. The colours of the layers may be such as to result in a subtractive black or approximately a black. Fig. 1 shows a three-colour material comprising silver halide layers I, II, III carried by a support a and coloured respectively blue-green, purple-red and yellow, the spectral absorption ranges of the different colours being indicated by cross hatching. Each layer is sensitized for a spectral region on the long-wave side of the absorption band as shown by asterisks ; thus layer III is sensitized for green, layer II for red and layer I for infra-red. The layers are copied behind three-colour selection pictures with the aid of filters corresponding to the sensitizations ; or they may be copied behind coloured master images obtained by superposing single images in basic colours obtained by mordanting, tanning or inhibition processes, or upon similar multilayer material. The developed silver images are converted into coloured images by destroying the dyestuff at the image a non-image portions in the manner described in Specifications 395,718, 397,159, 397,188 and 397,192 ; or by coupled reactions, by tanning with subsequent dissolution of the untanned portions, or by mordanting. In a modification, the colours of the three part layers are such that there are spectral gaps between the absorption bands of the different colours and the layers are sensitized in the region of such gaps. Thus Fig. 4 shows an exposure material in which the layers I, II, III are coloured respectively with Naphthol Green, Chloramine Red 7 B.L., and Mordant Yellow and are sensitized respectively with pinacyanol, erythrosin and blue. Coloured master pictures on this material are copied on to a three-colour material shown in Fig. 5, in which the part layers have similar colours, but the colours are such as to close the gaps in the absorption bands of the master images. Layers I, II, III are coloured respectively with Diamine Pure Blue FF, Sirius Violet and a yellow dye pervious to ultra-violet rays, the layers being sensitized respectively with Kryptocyanin, Acridine Orange and for ultra-violet. In another modification for three-colour pictures, the necessary sensitization is obtained by assigning two sensitizations to one of the ordinarv threecolour spectral zones and by choosing colouring dyes with appropriate absorption gaps. Fig. 6 shows a two-colour exposure material comprising a red-sensitive yellow-coloured layer I and a pale blue-green, blue-sensitive layer II. The yellow and pale-blue-green images are copied on to a two-layer material shown in Fig. 7, comprising an upper, blue-coloured, blue-sensitive layer II and a lower, red-coloured layer I sensitive to infra-red. Other examples of two- and three-colour materials are described. Suitable wash-out filter dyes may be added to the layers, if necessary. The colour of the master image may be independent of the actual colours of the object taken, or may be similar or complementary. The layers may be poured one over the other or may be arranged in bi-pack fashion. Specification 369,616 also is referred to. Reference has been directed by the Comptroller to Specification 375,338.